Low power biological sensing system

Abstract

It is recognized that, because of its unique properties, graphene can serve as an interface with biological cells that communicate by an electrical impulse, or action potential. Responding to a sensed signal can be accomplished by coupling a graphene sensor to a low power digital electronic switch that is activatable by the sensed low power electrical signals. It is further recognized that low power devices such as tunneling diodes and TFETs are suitable for use in such biological applications in conjunction with graphene sensors. While tunneling diodes can be used in diagnostic applications, TFETs, which are three-terminal devices, further permit controlling the voltage on one cell according to signals received by other cells. Thus, by the use of a biological sensor system that includes graphene nanowire sensors coupled to a TFET, charge can be redistributed among different biological cells, potentially with therapeutic effects.

The invention claimed is: 
     
       1. A low power sensing system suitable for use within a biological organism, the low power sensing system comprising:
 one or more graphene sensors, each graphene sensor having a first end and a second end, each first end configured to couple to a nerve cell of the biological organism, the graphene sensors configured to sense electrical signals originating from within the nerve cell and, in response, output sensed electrical signals; and 
 an implantable tunneling field effect transistor (TFET) being electrically coupled to the second end of the one or more the graphene sensors, the TFET being configured to be activated by the sensed electrical signals, the TFET having a source terminal and a gate terminal, the source terminal being coupled to the second end of a first one of the graphene sensors, and the gate terminal being coupled to the second end of a second one of the graphene sensors. 
 
     
     
       2. The sensing system of  claim 1  wherein the electrical signals are nerve cell impulses. 
     
     
       3. The sensing system of  claim 1  wherein at least one of the graphene sensors is configured as a nanowire. 
     
     
       4. The sensing system of  claim 1  wherein terminals of the TFET are arranged in a vertical orientation. 
     
     
       5. The sensing system of  claim 1  wherein the first end of the first one of the graphene sensors is coupled to a first biological cell, and the first end of the second one of the graphene sensors is coupled to a second biological cell. 
     
     
       6. The sensing system of  claim 1  wherein terminals of the TFET are coupled to different graphene sensors, each graphene sensor positioned in contact with a different nerve cell. 
     
     
       7. A biocompatible neurological sensor comprising:
 a first graphene nanowire that includes:
 a first end having an electrically conductive tip configured to be coupled to a first neuron; and 
 a second end; 
 
 a second graphene nanowire that includes:
 a first end having an electrically conductive tip configured to be coupled to a second neuron; and 
 a second end; and 
 
 an implantable tunneling field effect transistor (TFET) having a source terminal coupled to the second end of the first nanowire and having a gate terminal coupled to the second end of the second nanowire. 
 
     
     
       8. The biocompatible neurological sensor of  claim 7  wherein the first and second graphene nanowires are formed from a rolled graphene sheet. 
     
     
       9. The biocompatible neurological sensor of  claim 7 , wherein the electrically conductive tip is removably coupled to the graphene nanowire. 
     
     
       10. The biocompatible neurological sensor of  claim 7 , wherein the first and second graphene nanowires are configured to flexibly attach to the first and second neurons respectively by wrapping around a portion of the neuron. 
     
     
       11. The biocompatible neurological sensor of  claim 7  wherein the electrically conductive tip of the first and second graphene nanowires each includes an adhesive. 
     
     
       12. The biocompatible neurological sensor of  claim 7  wherein the electrically conductive tip of the first and second graphene nanowires each includes a surface feature that facilitates attachment to the neuron. 
     
     
       13. A device comprising:
 a biocompatible sensor having a first graphene nanowire and a second graphene nanowire, the graphene nanowires each having a first end and a second end, the first end of the first graphene nanowire configured to be coupled to a first nerve cell and the first end of the second graphene nanowire configured to be coupled to a second nerve cell, the biocompatible sensor configured to transmit low voltage electrical signals in response to an action potential from the first and second nerve cell; 
 an implantable tunneling field effect transistor (TFET) configured to respond to the low voltage electrical signals, a first terminal of the TFET being coupled to the second end of the first graphene nanowire and a second terminal of the TFET being coupled to the second end of the second graphene nanowire; and 
 an electronic circuit coupled to the TFET. 
 
     
     
       14. The device of  claim 13  wherein the electronic circuit includes an electronic memory configured to store information about the first and second nerve cells. 
     
     
       15. The device of  claim 13  wherein the TFET is configured to be coupled to a third nerve cell, the TFET being configured to control an action potential of the third nerve cell based on the low voltage electrical signals from the biocompatible sensor. 
     
     
       16. The sensing system of  claim 1  wherein the TFET includes a drain terminal coupled to the second end of a third one of the graphene sensors. 
     
     
       17. The biocompatible neurological sensor of  claim 7 , further comprising:
 a third graphene nanowire that includes:
 a first end having an electrically conductive tip configured to be coupled to a third neuron; and 
 a second end, the second end coupled to a third terminal of the TFET. 
 
 
     
     
       18. The device of  claim 13 , further comprising:
 a third graphene nanowire having a first end and a second end, the first end of the third graphene nanowire configured to be coupled to a first nerve cell, a third terminal of the TFET being coupled to the second end of the third graphene nanowire. 
 
     
     
       19. The device of  claim 13  wherein the action potential of the first and second nerve cells are nerve cell impulses. 
     
     
       20. The device of  claim 13  wherein terminals of the TFET are arranged in a vertical orientation.